236 research outputs found
Meta-Stock: Task-Difficulty-Adaptive Meta-learning for Sub-new Stock Price Prediction
Sub-new stock price prediction, forecasting the price trends of stocks listed
less than one year, is crucial for effective quantitative trading. While deep
learning methods have demonstrated effectiveness in predicting old stock
prices, they require large training datasets unavailable for sub-new stocks. In
this paper, we propose Meta-Stock: a task-difficulty-adaptive meta-learning
approach for sub-new stock price prediction. Leveraging prediction tasks
formulated by old stocks, our meta-learning method aims to acquire the fast
generalization ability that can be further adapted to sub-new stock price
prediction tasks, thereby solving the data scarcity of sub-new stocks.
Moreover, we enhance the meta-learning process by incorporating an adaptive
learning strategy sensitive to varying task difficulties. Through wavelet
transform, we extract high-frequency coefficients to manifest stock price
volatility. This allows the meta-learning model to assign gradient weights
based on volatility-quantified task difficulty. Extensive experiments on
datasets collected from three stock markets spanning twenty-two years prove
that our Meta-Stock significantly outperforms previous methods and manifests
strong applicability in real-world stock trading. Besides, we evaluate the
reasonability of the task difficulty quantification and the effectiveness of
the adaptive learning strategy
MetaAvatar: Learning Animatable Clothed Human Models from Few Depth Images
In this paper, we aim to create generalizable and controllable neural signed
distance fields (SDFs) that represent clothed humans from monocular depth
observations. Recent advances in deep learning, especially neural implicit
representations, have enabled human shape reconstruction and controllable
avatar generation from different sensor inputs. However, to generate realistic
cloth deformations from novel input poses, watertight meshes or dense full-body
scans are usually needed as inputs. Furthermore, due to the difficulty of
effectively modeling pose-dependent cloth deformations for diverse body shapes
and cloth types, existing approaches resort to per-subject/cloth-type
optimization from scratch, which is computationally expensive. In contrast, we
propose an approach that can quickly generate realistic clothed human avatars,
represented as controllable neural SDFs, given only monocular depth images. We
achieve this by using meta-learning to learn an initialization of a
hypernetwork that predicts the parameters of neural SDFs. The hypernetwork is
conditioned on human poses and represents a clothed neural avatar that deforms
non-rigidly according to the input poses. Meanwhile, it is meta-learned to
effectively incorporate priors of diverse body shapes and cloth types and thus
can be much faster to fine-tune, compared to models trained from scratch. We
qualitatively and quantitatively show that our approach outperforms
state-of-the-art approaches that require complete meshes as inputs while our
approach requires only depth frames as inputs and runs orders of magnitudes
faster. Furthermore, we demonstrate that our meta-learned hypernetwork is very
robust, being the first to generate avatars with realistic dynamic cloth
deformations given as few as 8 monocular depth frames.Comment: 17 pages, 9 figures. Project page:
https://neuralbodies.github.io/metavatar
Unified Attentional Generative Adversarial Network for Brain Tumor Segmentation From Multimodal Unpaired Images
In medical applications, the same anatomical structures may be observed in
multiple modalities despite the different image characteristics. Currently,
most deep models for multimodal segmentation rely on paired registered images.
However, multimodal paired registered images are difficult to obtain in many
cases. Therefore, developing a model that can segment the target objects from
different modalities with unpaired images is significant for many clinical
applications. In this work, we propose a novel two-stream translation and
segmentation unified attentional generative adversarial network (UAGAN), which
can perform any-to-any image modality translation and segment the target
objects simultaneously in the case where two or more modalities are available.
The translation stream is used to capture modality-invariant features of the
target anatomical structures. In addition, to focus on segmentation-related
features, we add attentional blocks to extract valuable features from the
translation stream. Experiments on three-modality brain tumor segmentation
indicate that UAGAN outperforms the existing methods in most cases.Comment: 9 pages, 4 figures, Accepted by MICCAI201
Research on the Problem of Old-Age Care in China From the Perspective of Ethics
The elders are an important driving force for economic development, social progress and national prosperity. The care of the elderly, as a universal world problem, is related to their dignity, human rights and social stability. Since 2000, China has stepped into the threshold of an aging society. With the increasing aging population and the influence of population, economy, culture, politics and other uniquely national conditions, the conflicts and problems over providing for the aged are more complicated and severe. It has become an urgent issue in China how to solve a series of ethical dilemmas of providing for the aged caused by the aging population.Firstly, we use the data of the 2018 Chinese Longitudinal Healthy Longevity Survey (CLHLS) for positivist research, and then adopt the ordered Probit regression model for analysis. Secondly, we present and discuss the existing ethical problems of providing for the aged in society: firstly, the unfairness of allocation of resources in the society for providing for the aged; secondly, the dilution of concept of filial piety in family; thirdly, the weakening of the trend of respecting the elderly in society; last but not least, the lack of good in old-age security system. In view of the above-mentioned ethical problems of providing for the aged in China, we propose some solutions, namely, fairly distributing old-age resources in society; promoting the cultural tradition of filial piety; improving the system of endowment policy. Focusing on the ethical issues of old-age care, this paper provides some ethical thoughts for the solution of them
InterroLang: Exploring NLP Models and Datasets through Dialogue-based Explanations
While recently developed NLP explainability methods let us open the black box
in various ways (Madsen et al., 2022), a missing ingredient in this endeavor is
an interactive tool offering a conversational interface. Such a dialogue system
can help users explore datasets and models with explanations in a
contextualized manner, e.g. via clarification or follow-up questions, and
through a natural language interface. We adapt the conversational explanation
framework TalkToModel (Slack et al., 2022) to the NLP domain, add new
NLP-specific operations such as free-text rationalization, and illustrate its
generalizability on three NLP tasks (dialogue act classification, question
answering, hate speech detection). To recognize user queries for explanations,
we evaluate fine-tuned and few-shot prompting models and implement a novel
Adapter-based approach. We then conduct two user studies on (1) the perceived
correctness and helpfulness of the dialogues, and (2) the simulatability, i.e.
how objectively helpful dialogical explanations are for humans in figuring out
the model's predicted label when it's not shown. We found rationalization and
feature attribution were helpful in explaining the model behavior. Moreover,
users could more reliably predict the model outcome based on an explanation
dialogue rather than one-off explanations.Comment: EMNLP 2023 Findings. Camera-ready versio
Full-sky ray-tracing simulation of weak lensing using ELUCID simulations: exploring galaxy intrinsic alignment and cosmic shear correlations
The intrinsic alignment of galaxies is an important systematic effect in
weak-lensing surveys, which can affect the derived cosmological parameters. One
direct way to distinguish different alignment models and quantify their effects
on the measurement is to produce mocked weak-lensing surveys. In this work, we
use full-sky ray-tracing technique to produce mock images of galaxies from the
ELUCID -body simulation run with the WMAP9 cosmology. In our model we assume
that the shape of central elliptical galaxy follows that of the dark matter
halo, and spiral galaxy follows the halo spin. Using the mocked galaxy images,
a combination of galaxy intrinsic shape and the gravitational shear, we compare
the predicted tomographic shear correlations to the results of KiDS and DLS. It
is found that our predictions stay between the KiDS and DLS results. We rule
out a model in which the satellite galaxies are radially aligned with the
center galaxy, otherwise the shear-correlations on small scales are too high.
Most important, we find that although the intrinsic alignment of spiral
galaxies is very weak, they induce a positive correlation between the
gravitational shear signal and the intrinsic galaxy orientation (GI). This is
because the spiral galaxy is tangentially aligned with the nearby large-scale
overdensity, contrary to the radial alignment of elliptical galaxy. Our results
explain the origin of detected positive GI term from the weak-lensing surveys.
We conclude that in future analysis, the GI model must include the dependence
on galaxy types in more detail.Comment: 23 pages, 13 figures, published in ApJ. Our mock galaxy catalog is
available upon request by email to the author ([email protected],
[email protected]
Kaposi’s Sarcoma-Associated Herpesvirus Reduces Cellular Myeloid Differentiation Primary-Response Gene 88 (MyD88) Expression via Modulation of Its RNA
Kaposi’s sarcoma (KS)-associated herpesvirus (KSHV) is a human gammaherpesvirus associated with several human malignancies. The replication and transcription activator (RTA) is necessary and sufficient for the switch from KSHV latency to lytic replication. Interleukin 1 (IL-1) is a major mediator for inflammation and plays an important role in both innate and adaptive immunity. Myeloid differentiation primary response gene 88 (MyD88) is an essential adaptor molecule for IL-1 as well as most Toll-like receptor signaling. In this study, we identified a novel mechanism by which KSHV interferes with host inflammation and immunity. KSHV RTA specifically reduces the steady-state protein levels of MyD88, and physiological levels of MyD88 are downregulated during KSHV lytic replication when RTA is expressed. The N-terminal region of RTA is required for the reduction of MyD88. Additional studies demonstrated that RTA targets MyD88 expression at the RNA level, inhibits RNA synthesis of MyD88, and may bind MyD88 RNA. Finally, RTA inhibits IL-1-mediated activation of NF-B. Because IL-1 is abundant in the KS microenvironment and inhibits KSHV replication, this work may expand our understanding of how KSHV evades host inflammation and immunity for its survival in vivo
- …